Durable press method

ABSTRACT

A method of treating fabric articles to impart a durable press thereto comprises subjecting the articles to steam in a rising temperature due to the steam, subjecting the articles to formaldehyde and sulphur-dioxide vapors and steam at a higher temperature, allowing the temperature to fall, circulating air from the outside to remove steam and free chemicals and circulating dry heated air in a closed system to raise the temperature of the articles to around 250*F. Finally, cool air and water spray are employed to return the articles to room temperature.

O Umted States Patent 11 1 1111 3,865,545 Forg et al. Feb. 11, 1975 [54] DURABLE PRESS METHOD (Rrvusszlllft al..l sll;

, etce eta. 11.4 1 lnvemmfi 9" L'payeiboth 3,653,805 4/1972 Gamarra etal s/11e.4 ofC1nmnat1.0h10 3,660,013 5/1972 Payet et al. 8/1 16.4

[73] Assignee: McGraw-Edison Company, Elgin,

' lll. Primary Examiner-Stephen J. Lechert, Jr. [22] Filed. Dec 12 1972 Attorney, Agent, or Firm-George H. Fritzinger [21] Appl. No.: 314,382 ABSTRACT .Related U'S' Apphcauon Data A method of treating fabric articles to impart a dura- [62] 1;5 6 Sept 131 ble press thereto comprises subjecting the articles to steam in a rising temperature due to the steam. sub

jecting the articles to formaldehyde and sulphur- [52] US. Cl 8/116 R, 8/1 16.4, 84/111366; dioxide vapors and Steam at a higher temperature 51 I t Cl D06 6 lowing the temperature to fall, circulating air from the 1 6 outside to remove steam and free chemicals and circu- 1 0 care 2 lating dry heated air in a closed system to raise the temperature of the articles to around 250F. Finally, cool air and water spray are employed to return the [56] UNITE SZIFXFFZS SX TENTS articles to room temperature. 3,264,054 8/1966 Reinhardt et al. 8/l 16.4 x 6 Claims, 9 Figures PM'ENTEI] FEB] H975 SHEET 1. OF 5 I l I I I I I I I l L PATENIED 1 3,865,545

SHEET 3 OF 5 PATENTED 11975 3, 865 545 sum u 0F 5 g 35 g FIG.8

PATENIED 1 I975 3, 865.545

SHEET 5 UF 5 FIG. 9

TE MPE RA TURE 123456789/0/ISTEPS STEAM INJ ECTION AND COOLING ONLY DURABLE PRESS METHOD This application is a division of our application Ser. No. 179,78l, filed Sept. 13, l97l and entitled Dura ble Press Method and Apparatus and issued June 12. I973. as Pat. No. 3,738,019.

An object of the invention is to provide an improved method for the purpose stated which can be carried out efficiently and economically and with consistent results.

Another object is to provide an improved method of producing a durable press wherein after the fabric arti' cles are treated with sulphur dioxide, formald h d gas and steam the treating chamber is first subjected to an exhaust heating to rid the atmosphere primarily of steam and then to a closedcircuit heating to bring the fabric articles to a temperature of at least 250F.

Another object is to provide an improved method of producing a durable press wherein as a first step the articles are treated with steam in the treating chamber to provide them with the desired moisture content without affecting the original press of the articles.

These and other objects and features of our invention will be apparent from the following description and the appended claims.

In the description of our invention reference is had to the accompanying drawings of which:

FIG. 1 is a top plan diagram of a treating apparatus according to our invention;

FIG. 2 is a cross sectional view taken on the line 2--2 of FIG. 1;

FIG. 3 is a fractional sectional view on line 3--3 of FIG. 2;

FIG. 4 is a fractional sectional view illustrating a double seal for the doors;

FIGS. 5-8 are diagrammatic cross sectional views similar to FIG. 2 illustrating different basic steps em ployed in the method of the invention for treating fabric articles to provide them with a durable press; and

FIG. 9 is a graph showing a typical temperature-time cycle of the present treating method.

An apparatus for carrying out the present method comprises an oblong box 10 rectangular in cross section having double walls 11 (FIG. 2) for effective insulation enclosing an elongate treating chamber 12. At the opposite ends of the box (FIG. 1) are doors 13 mounted on hinges 14 and secured by suitable latches 15. The double-door arrangement is provided to permit loading of the chamber at one end and unloading of finish articles at the other end at the same time.

Each door 13 engages the rim 16 of the box around the door opening in a double seal arrangement, shown in FIG. 4, to prevent the escape of any gases during a press cycle. This double seal comprises a slot 17 in the rim 16 of the box in which is secured a strip of silicone sponge material 18. Along the border of each door is a similar slot 19 offset slightly from the slot 17 and in which is a strip 20 of silicone sponge material. When the door is closed the flange 21 at the outer side of the slot 19 of the door impinges against the silicone sponge strip l8 and the flange 22 of the box at the inner side of the slot 17 impinges against the silicone sponge strip 20 to provide a double seal with the capture of air space between the flanges 21 and 22 and sponge strips 18 and 19. This captured air space is effective in preventing any leakage of gases from the treating chamber to the outside.

Spaced from the top of the box is a slotted ceiling 23 forming an air distributing chamber or manifold 24 running the length of the treating chamber 12. Midway the length of the box 10 is a side compartment 25 housing an air conduit 26 running from the bottom of the chamber 12 to the manifold 24. This air conduit has a blower 27 in its lower end portion and a heat exchanger 28 where it opens into the manifold 24. The blower circulates air through the chamber 12 from the top to the bottom thereof. Leading from the conduit 26 at points spaced in the direction of circulation are an exhaust duct 29 and an air inlet duct 30. The exhaust duct 29 has a damper 31 pivoted at 32 for opening and closing the duct (FIGS. 6 and 8). Also, the inlet duct has a damper 33 hinged at 34 to the wall of the conduit between the two ducts for shiftable movement between a closed position (FIG. 5) and an open position (FIG. 6) wherein the damper closes the conduit 26 between the two ducts to force air circulation from the outside via the inlet duct 30, heat exchanger 28, manifold 24, treating chamber 12, blower 27 and exhaust duct 29 back to the outside atmosphere.

At the top of the box are three equally spaced panel blowers 35 (FIGS. 1 and 2) which circulate air through the space 36 between the double walls 11 and then out via a single centrally located exhaust duct 37 (FIG. 1). Between the double walls 11 there are also suitable spray headers 38 connectable to a source of cooling water (not shown) for directing the water against the walls of the treating chamber to reduce the tempera ture thereof to room temperature after each treating cycle.

At the bottom of the treating chamber 12 there are headers 39 for injecting steam upwardly onto garments 40 mounted on hangers 4I attached to top rails 42 running the length of the chamber. Also. at the bottom of the treating chamber I2 there is a header 43 for introducing sulphur dioxide gas. Still further. there is a heater plate 44 near the bottom of the chamber or receiving paraformaldehyde discharged from a hopper 45 by way of a tube 46 as by means of a ram, screw conveyor or stoker generally indicated at 47.

The slotted ceiling 23 comprises two rows of spaced panels 48 inclined from a plane midway the width of the chamber 12 to the opposite sides thereof. The panels 48 are of a U-channel form each having a relatively short upturned flange 49 along its edge farthest from the plane L midway the length of the chamber and a higher flange 50 along its opposite edge nearer the plane L of which the upper portion of the latter flange 50 is turned over horizontally at 51 towards the plane L to overlie the shorter flange 49 of the next adjacent panel nearer the plane L at a spacing therefrom equal to the spacing between the panel and the stated next adjacent panel. Further, the spacing between the panels is increased progressively proceeding from the center plane L to the ends of the chamber. In this way pro gressively larger louvers 52 are formed proceeding from the plane L to the ends of the chamber. which are directed to the catch the air in the manifold 24 flowing from the central conduit 26 and to direct it downwardly into the chamber 12. Further, since each panel is inclined downwardly towards the sides and is of an upright U-channel form it catches the water of condensation and flows it down to the side walls of the chamber to lessen the chance of drippage on the garments 40 being processed.

In carrying out the treating method of our invention the garments 40 are equally spaced along the length of the treating chamber 12 and the doors 13 are closed. If the relative humidity of the outside atmosphere is below 20 percent, three preliminary steps are first carried out to introduce the proper amount of moisture into the garments without affecting the crease or finish with which the garments have been pre-pressed, by (l) injecting steam in the treating chamber 12 from the headers 39 for about 20 seconds while the circulating blower 27 is off, the exhaust damper 31 open, the inlet damper 33 closed and the heat exchanger 28 off to cause the temperature in the chamber to rise from about 95F to about I20F (FIG. (2) cutting off the steam injection to allow the garments 40 to soak in the steam atmosphere for about 2 minutes while allowing the temperature to fall to about 1 F; and (3) circulating air from the outside via the inlet duct 30, treating chamber 12 and exhaust duct 29 for about 3 minutes while the inlet damper 33 is open (FIG. 6) to cause the temperature in the treating chamber to fall back to the starting point of about 95F.

A next step (4) which would be the initial step of the press cycle if the relative humidity of the outside atmosphere is above percent comprises injecting chemicals into the treating chamber 12 while the panel blowers 35 are still on, the exhaust damper 31 open, the inlet damper 33 closed and the blower 27 and heat exchanger 28 both off (FIG. 5) by (a) heating paraformaldehyde fed onto the heating plate 44 until it is vaporized and diffused through the treating chamber 12,

(b) injecting steam by the headers 39, and (c) injecting sulphur dioxide gas from the header 43 all for a duration of about 45 seconds causing the temperature in the chamber to rise to a temperature of from l20F to 145F. By way of preferred example, a measured amount of sulphur dioxide gas is injected by filling a tank, which would have the right amount of gas at atmospheric pressure, to a pressure of 2 atmospheres and bleeding off until the pressure falls to atmospheric. In a broader sense, the gas may be stored to a given higher pressure, so long as the vapor pressure is not reached, and is then bled off until a predetermined lower pressure is reached.

A next step (5) is carried out by cutting off the steam to allow the temperature to fall and by preferably continuing to inject sulphur dioxide gas and formaldehyde gas. Typically, the garments may thus be allowed to soak in the treating atmosphere for about 5 minutes until the temperature in the chamber falls at least 10F and permissibly as much as 30F depending on the temperature to which the chamber was heated by the steam (FIG. 5). This step enables an effective durable press to be obtained in an efficient manner as is described in our pending application aforementioned.

An exhaust heating step (6) is next carried out with the panel blower 35 off, the main blower 27 on, the exhaust damper 31 open, the inlet damper 33 open and the heat exchanger 28 on, (FIG. 7) but with all injection of steam and chemicals to the chamber now turned off so as only to circulate heated air from the'outside through the treating chamber to remove steam as well as any free chemicals from the garments for a period of about 2 minutes; during this step the temperature may typically be raised to about 180F (FIG. 9). Next, a closed-circuit heating step (7) is carried out for about 5 to 7 minutes which differs from the preceding heating step in that the inlet damper 33 and exhaust damper 29 are closed (FIG. 8) to cause the air to circulate internally through the heat exchanger 28 to bring the temperature of the atmosphere typically to about 280 as shown in FIG. 9, the purpose being to heat the articles being treated to at least 250F. A final step (8) of the treating cycle is to carry out an exhaust cooling (FIG. 6) for about 30 seconds to bring the temperature down to about 200F.

Finally, the garments are subjected to a series of cleaning steps to rid the garments of residual odors and to bring the temperature down to about room temperature as follows: a first cleaning step (9) is carried out for about 3 to 7 minutes by injecting steam while the panel blower is off, the heat exchanger 28 is off. the inlet damper 33 closed, the exhaust damper 31 open and the main blower 27 off (FIG. 5) until the internal temperature rises to about 220F; a next cleaning step (10) is carried out for about 5 minutes by turning the panel blower 35 on, opening the inlet damper 33 and turning the main blower 27 on until the temperature is lower to about l80F and a final load-unload step (11) is carried out by continuing the preceding step for about 1 /2 minutes during which time water is also sprayed into interwall space 36 against the wall of the heating chamber 12 from the headers 38 to cool down the temperature of the walls of the treating chamber to about the starting temperature of 95 F.

The embodiment of our invention herein specifically described is intended to be illustrative and not necessarily limitative of our invention since the same is subdue to the steam, subjecting the material to formaldehyde and sulphur-dioxide vapor agents and to steam in an environment of a temperature higher than that of the material, subjecting the material to circulating air to remove moisture and said agents therefrom, and then heating the material to a temperature of the order of 250 F.

2. The method set forth in claim 1 wherein said firststated step comprises injecting steam into a chamber containing said material to raise the temperature of the environment from that of the atmosphere to around F, cutting off the steam and allowing the material to soak in the steam atmosphere for several minutes and the circulating outside air to drop the temperature of said environment to the starting value.

3. The method set forth in claim 1 wherein said last two steps include in the sequence named an exhaustheating operation comprising circulating air through the material from the outside while concurrently heating the circulating air, and a closed-circuit heating operation wherein the atmosphere around the material is heated until the temperature of said material reaches a value of the order of 250 F.

4. The method set forth in claim 1 wherein said treating steps are carried out in a treating chamber including the spraying of water against the walls of said treating chamber after the temperature in said chamber reaches approximately 250 F. to cool said walls sub stantially to room temperature.

5. The method set forth in claim 3 wherein the temperature in said chamber is raised to a value from 120F to 145F by the injection of steam with the vapor agents and is then allowed to fall by at least F after the steam is cut off, and wherein said temperature is raised to the order of 180F at the end of said exhaustheating step and is thereupon raised to at least 250F.

6. In a method of treating fabric articles to impart thereto a durable press using a treating chamber and means for circulating air through said chamber via a blower in a side conduit including air exhaust and inlet ducts and a heat exchanger: the steps of providing fabric articles in said treating chamber having a predetermined moisture content free of polymer-forming precondensates, injecting sulphur dioxide and formaldehyde gases and steam into said chamber to cause said gases and steam to permeate said aricles in a rising temperature until said temperature reaches a value of from I20F to F, cutting off said steam injection to allow the temperature in said chamber to fall below said value, heating said chamber by said heat exchanger first by an exhaust circulation of air until the temperature in the chamber reaches the order of F and then by a closed circulation of air until the temperature in said chamber reaches at least 250F and then circulating outside air through said chamber and spraying the walls of said chamber with water to cool the articles in said chamber prior to the removal of the same. 

1. IN A METHOD OF TREATING CELLULOSE-CONTAINING MATERIAL TO IMPART A DURABLE PRESS THERETO: THE STEPS OF INTRODUCING MOISTURE FREE OF POLYMER-FORMING PRECONDENSATED INTO SAID MATERIAL BY SUBJECTING SAID MATERIAL TO STEAM AND RAISING THE TEMPERATURE OF THE ENVIRONMENT DUE TO THE STEAM, SUBJECTING THE MATERIAL TO FORMALDEHYDE AND SULPHUR-DIOXIDE VAPOR AGENTS AND TO STEAM IN AN ENVIRONMENT OF A TEMPERATURE HIGHER THAN THAT OF THE MATERIAL, SUBJECTING THE MATERIAL TO CIRCULATING AIR TO REMOVE MOISTURE AND SAID AGENTS THEREFROM, AND THEN HEATING THE MATERIAL TO A TEMPERATURE OF THE ORDER OF 250*F.
 2. The method set forth in claim 1 wherein said first-stated step comprises injecting steam into a chamber containing said material to raise the temperature of the environment from that of the atmosphere to around 120*F, cutting off the steam and allowing the material to soak in the steam atmosphere for several minutes and the circulating outside air to drop the temperature of said environment to the starting value.
 3. The method set forth in claim 1 wherein said last two steps include in the sequence named an exhaust-heating operation comprising circulating air through the material from the outside while concurrently heating the circulating air, and a closed-circuit heating operation wherein the atmosphere around the material is heated until the temperature of said material reaches a value of the order of 250* F.
 4. The method set forth in claim 1 wherein said treating steps are carried out in a treating chamber including the spraying of water against the walls of said treating chamber after the temperature in said chamber reaches approximately 250* F. to cool said walls substantially to room temperature.
 5. The method set forth in claim 3 wherein the temperature in said chamber is raised to a value from 120*F to 145*F by the injection of steam with the vapor agents and is then allowed to fall by at least 10*F after the steam is cut off, and wherein said temperature is raised to the order of 180*F at the end of said exhaust-heating step and is thereupon raised to at least 250*F.
 6. In a method of treating fabric articles to impart thereto a durable press using a treating chamber and means for circulating air through said chamber via a blower in a sidE conduit including air exhaust and inlet ducts and a heat exchanger: the steps of providing fabric articles in said treating chamber having a predetermined moisture content free of polymer-forming precondensates, injecting sulphur dioxide and formaldehyde gases and steam into said chamber to cause said gases and steam to permeate said aricles in a rising temperature until said temperature reaches a value of from 120*F to 145*F, cutting off said steam injection to allow the temperature in said chamber to fall below said value, heating said chamber by said heat exchanger first by an exhaust circulation of air until the temperature in the chamber reaches the order of 180*F and then by a closed circulation of air until the temperature in said chamber reaches at least 250*F and then circulating outside air through said chamber and spraying the walls of said chamber with water to cool the articles in said chamber prior to the removal of the same. 